Head And Neck – Pathology

• Location: Base of tongue = oropharyngeal region

• Patient is a non-smoker: Raises suspicion for a non-smoking-related cause

• HPV, especially type 16, is a major cause of oropharyngeal squamous cell carcinoma — even in nonsmokers and non-drinkers

• These HPV-related tumors often have better prognosis than tobacco-related ones

• Long-standing ulcer with irregular borders is typical of malignant infiltration

❌ Other Options:

• Candida albicans – Can cause oral thrush or chronic mucocutaneous candidiasis but not carcinoma

• Herpes simplex virus (HSV) – Causes painful vesicles/ulcers but not associated with oral cancer

• Treponema pallidum – Causes syphilitic ulcers, especially in early stages; not linked to carcinoma

• Epstein-Barr virus (EBV) – Linked to nasopharyngeal carcinoma, not typically base of tongue SCC

White patch on oral mucosa that can’t be scraped off

Strongly associated with chronic tobacco use

Histology shows squamous epithelial thickening (hyperkeratosis, possibly dysplasia)

Premalignant → can progress to carcinoma in situ over time

❌ Other options:

• Aphthous ulcer – Painful, shallow sore; not white, not premalignant

• Oral thrush – White, but can be scraped off; fungal cause

• Lichen planus – Lacy white lines (Wickham striae); autoimmune; not classic for malignancy

• Pyogenic granuloma – Red, vascular nodule; bleeds easily; not white or precancerous

• Fibroma is a common benign, fibrous proliferative lesion in the oral cavity. It typically occurs as a reaction to chronic irritation or trauma, and it presents as a firm, smooth, and non-tender growth.

Why the other options are wrong:

1. Erythroplakia: This is a red, velvety patch in the oral mucosa, often associated with a higher risk of malignant transformation, but it is not fibrous in nature.

2. Glaucoma: This refers to a condition of increased intraocular pressure affecting the eye, not related to the oral cavity.

3. Leukoplakia: These are white patches in the oral mucosa, often precancerous, but again, not fibrous.

4. Pyogenic granuloma: This is a vascular lesion that often presents as a red, soft, and friable growth, which is different from the fibrous nature of a fibroma.

• Appearance: Foamy, white-to-silver plaques on the bulbar conjunctiva (near the limbus).
• Cause: Vitamin A deficiency (leads to keratinization of conjunctival epithelium).
• Associated with: Night blindness (nyctalopia) and xerophthalmia.

Why Other Options Are Wrong:

1. Seen in neovascularization → Incorrect (neovascularization is seen in corneal hypoxia or diabetic retinopathy, not Bitot spots).
2. Clouding of cornea → Incorrect (this describes corneal opacity, not Bitot spots).
3. Blood in cornea → Incorrect (this suggests hyphema or corneal hemorrhage, unrelated to Bitot spots).
4. Seen in glaucoma → Incorrect (glaucoma causes optic nerve damage, not conjunctival changes).

Acute angle-closure glaucoma (AACG) is a medical emergency caused by a sudden increase in intraocular pressure (IOP) due to blockage of the trabecular meshwork at the iridocorneal angle. This prevents aqueous humor drainage, leading to a rapid rise in IOP.

Key features of AACG:

• Raised intraocular pressure (IOP) → Can exceed 40-50 mmHg

• Red eye → Due to vascular congestion

• Shallow anterior chamber → Caused by forward displacement of the iris

• Headache, nausea, and vomiting → Due to autonomic activation from severe eye pain

• Halos around lights and blurred vision

Why the Other Options Are Wrong:

• Open-angle glaucoma ❌

• Chronic and usually asymptomatic in early stages.

• No acute symptoms like headache, nausea, or severe pain.

• Hyphema ❌

• Blood in the anterior chamber, usually due to trauma, but does not cause sudden IOP rise or systemic symptoms.

•  Cataracts ❌

• Gradual loss of vision with lens opacification, no acute pain or IOP increase.

•  Uveitis ❌

• Inflammation of the uveal tract (iris, ciliary body, choroid).

• Causes pain, photophobia, and redness but usually not a rapid IOP increase or nausea/vomiting.

Nasopharyngeal carcinoma (NPC) is strongly associated with Epstein-Barr virus (EBV), especially in endemic regions like Southern China, Southeast Asia, and North Africa. EBV contributes to oncogenesis by:

• Infecting epithelial and lymphoid cells, leading to genetic mutations

• Suppressing immune responses, allowing uncontrolled cell growth

NPC is commonly of the undifferentiated or non-keratinizing squamous cell carcinoma type.

Why the Other Options Are Wrong:

• Hepatitis B virus (HBV) ❌

• HBV is associated with hepatocellular carcinoma (HCC), not nasopharyngeal carcinoma.

•  Cytomegalovirus (CMV) ❌

• CMV is linked to congenital infections and immunocompromised conditions but not NPC.

•  Hepatitis C virus (HCV) ❌

• HCV is linked to liver cancer (HCC), not NPC.

• Human immunodeficiency virus (HIV) ❌

• HIV increases the risk of Kaposi sarcoma, lymphoma, and other opportunistic infections, but it is not directly linked to NPC.

Mucoepidermoid carcinoma is the most common malignant tumor of the salivary glands, especially the parotid gland. It arises from both mucous and epidermoid (squamous) cells and has varying grades:

• Low-grade: Slow-growing, better prognosis

• High-grade: Aggressive, poor prognosis

Why the Other Options Are Wrong:

• Option: Warthin tumor ❌

• A benign tumor of the parotid gland, associated with smoking.

• Option: Oncocytoma ❌

• A rare, benign salivary gland tumor composed of oncocytes (cells with abundant mitochondria).

• Option: Adenoid cystic carcinoma ❌

• A malignant tumor but less common than mucoepidermoid carcinoma. It has a tendency for perineural invasion and slow but aggressive growth.

• Option: Pleomorphic adenoma ❌

• The most common benign salivary gland tumor, but not malignant. It has a small risk of malignant transformation.

Xerostomia refers to dryness of the oral cavity due to reduced or absent salivary flow. It can result from various conditions, including:

• Dehydration

• Sjogren’s syndrome (autoimmune destruction of salivary glands)

• Radiation therapy (damage to salivary glands)

• Medications (anticholinergics, antihistamines, diuretics)

• Diabetes mellitus

Why the Other Options Are Wrong:

• Option: Steatorrhea → This refers to fatty stools, which occur due to malabsorption disorders (e.g., pancreatitis, celiac disease). It has no relation to oral dryness.

• Option: Sialolithiasis → This refers to the formation of salivary gland stones, which can lead to obstruction and swelling but does not directly define oral dryness.

• Option: Keratosis → This is an abnormal thickening of the skin or mucous membranes, often due to chronic irritation or precancerous changes. It is not related to salivary function.

• Option: Sialorrhea → This refers to excessive salivation (opposite of xerostomia) and is seen in conditions like Parkinson’s disease and cerebral palsy.

Squamous papilloma is a benign epithelial growth caused by low-risk HPV strains 6 and 11. These HPV types lead to non-cancerous lesions affecting the skin and mucosal surfaces, including the oral cavity, respiratory tract, and genital region. Squamous papillomas are characterized by exophytic, cauliflower-like growths.

Why the Other Options Are Wrong:

•  HPV 16 & 18 → These are high-risk HPV types associated with malignant conditions like cervical cancer, oropharyngeal cancer, and squamous cell carcinoma. They do not typically cause benign squamous papillomas.

• Coronavirus → This family of viruses primarily causes respiratory illnesses (e.g., SARS, MERS, COVID-19) and does not induce squamous papillomas.

•  EBV (Epstein-Barr virus) → EBV is linked to nasopharyngeal carcinoma, Burkitt’s lymphoma, and oral hairy leukoplakia, not squamous papillomas.

•  Adenovirus → Known for causing respiratory infections, conjunctivitis, and gastroenteritis, but not papillomas.

Sialadenitis is inflammation of a salivary gland, commonly affecting the parotid gland due to bacterial infections (like Staphylococcus aureus) or viral infections (like mumps).

However, when sialadenitis affects the submandibular gland, it is often secondary to a stone (sialolithiasis). The submandibular gland is more prone to stone formation due to:

•Its upward ductal flow (Wharton’s duct), which can cause stasis.

•Its alkaline and mucus-rich saliva, which promotes stone formation.

•The long and tortuous course of Wharton’s duct, increasing the risk of blockage.

A stone (sialolith) in the duct leads to saliva stasis, allowing bacterial overgrowth and subsequent infection and inflammation of the gland.

Why the Other Options Are Wrong:

Infection by Staphylococcus aureus (Incorrect choice) – While S. aureus is a common cause of bacterial sialadenitis, submandibular sialadenitis is usually secondary to an obstruction, such as a stone, rather than a primary bacterial infection.

.Infection by mumps virus (Incorrect choice) – Mumps mainly affects the parotid gland, not the submandibular gland.

Sjogren syndrome (Incorrect choice) – An autoimmune disease that causes chronic inflammation and dry mouth, but it is not the primary cause of acute sialadenitis.

Inflammation (Incorrect choice) – While inflammation is present, the cause in the submandibular gland is usually secondary to a stone, not just random inflammation.

Diabetes, particularly when poorly controlled, can lead to several eye problems that result in visual impairment. The major causes of visual impairment in people with diabetes are associated with diabetic retinopathy and other diabetic eye complications. Let’s break down each option to understand its role in visual impairment caused by diabetes.

Damage to the Rods (Correct Answer)

• Rods are photoreceptor cells in the retina that are responsible for vision in low light (night vision). While diabetes can cause damage to the retina, the damage typically affects the blood vessels and leads to diabetic retinopathy (which involves the macula and retina as a whole). However, damage to rods is not typically a direct cause of visual impairment in diabetes. The primary issue in diabetic retinopathy is the blood vessels of the retina, not direct damage to rods. Therefore, damage to the rods is not the most common or primary cause of visual impairment in diabetic patients.

Occlusion of Retinal Arteries

• Retinal artery occlusion is a condition that can occur in people with diabetes and results in vision loss. Diabetic retinopathy and associated changes in the blood vessels increase the risk of occlusion (blockage) of retinal arteries, leading to sudden vision loss. So, retinal artery occlusion is indeed a cause of visual impairment in diabetes.

Cataract at an Early Age

• Cataracts (clouding of the lens) are more common in people with diabetes, and they tend to develop at an earlier age than in the general population. Chronic high blood sugar levels contribute to the formation of cataracts, leading to blurry vision and visual impairment. This is a well-documented complication of diabetes.

Retinal Detachment

• Retinal detachment is a serious complication of diabetic retinopathy. It occurs when the retina, particularly the macula, pulls away from the underlying tissues, leading to sudden and severe vision loss. Diabetic retinopathy, especially in its proliferative form, can lead to retinal detachment due to abnormal blood vessel growth and bleeding.

Neovascularization

• Neovascularization refers to the growth of new, abnormal blood vessels in the retina, which is a hallmark of proliferative diabetic retinopathy. These new blood vessels are fragile and prone to leaking blood and fluid, leading to vision impairment. Neovascularization is a major cause of visual impairment in advanced diabetic retinopathy.

Final Answer: Damage to the Rods

The damage to rods is not the primary cause of visual impairment in diabetes. The main causes are related to vascular changes in the retina (like retinal artery occlusion, neovascularization, retinal detachment) and lens opacity (cataracts), rather than direct damage to the rods.

Why the Other Options Are Correct:

1. Occlusion of Retinal Arteries: This is a common cause of vision loss in diabetes due to vascular damage.
2. Cataract at an Early Age: People with diabetes are more prone to developing cataracts earlier than the general population.
3. Retinal Detachment: This is a severe complication of proliferative diabetic retinopathy and leads to visual impairment.
4. Neovascularization: Abnormal blood vessel growth in the retina (neovascularization) is a major cause of vision loss in proliferative diabetic retinopathy.

The most common cause of blindness in individuals with diabetes is diabetic retinopathy. Let’s explore this and the other options to understand why:

1. Diabetic Retinopathy (Correct Answer)

• Cause: Diabetic retinopathy is a complication of diabetes that affects the blood vessels of the retina, the light-sensitive tissue at the back of the eye. Over time, high blood sugar levels can damage these blood vessels, causing them to leak fluid or blood, leading to vision loss.

• Progression: There are two stages:

  • Non-proliferative diabetic retinopathy (NPDR): Early stage, where blood vessels in the retina become weak and leaky.
  • Proliferative diabetic retinopathy (PDR): Advanced stage, where new blood vessels grow abnormally in the retina, leading to bleeding and retinal detachment.

• Reason for blindness: Diabetic retinopathy can lead to severe vision impairment and blindness if left untreated. It’s a leading cause of blindness in working-age adults due to the impact on the retina.

2. Corneal Opacity

• Cause: Corneal opacity refers to clouding of the cornea, the transparent front layer of the eye. It can result from infection, trauma, or certain diseases, but is not the most common cause of blindness in diabetes.

• Relevance: While diabetes can increase the risk of corneal infections or reduce wound healing, corneal opacity is not the leading cause of blindness in diabetic patients.

3. Conjunctivitis

• Cause: Conjunctivitis is inflammation of the conjunctiva, the thin membrane covering the white part of the eye. It is commonly caused by infections (viral or bacterial), allergies, or irritants.

• Relevance: Although people with diabetes may be more susceptible to infections, conjunctivitis does not cause permanent blindness. It is usually a temporary condition and does not directly affect vision in the long term.

4. Lens Dislocation

• Cause: Lens dislocation refers to the displacement of the lens from its normal position in the eye. This can occur due to trauma, genetic conditions like Marfan syndrome, or certain eye diseases. While lens dislocation can cause visual disturbances, it is not the most common cause of blindness in people with diabetes.

• Relevance: Diabetic patients are at higher risk for cataracts (clouding of the lens), which can affect vision, but lens dislocation is a rare cause of blindness in diabetes.

5. Glaucoma

• Cause: Glaucoma is a group of eye diseases that damage the optic nerve, often due to increased intraocular pressure. It can lead to vision loss and blindness. While diabetes increases the risk of developing glaucoma, it is not the most common cause of blindness in people with diabetes.

• Relevance: Glaucoma does contribute to blindness, but diabetic retinopathy is a more common cause of blindness among diabetic patients.

Final Answer: Retinopathy

Diabetic retinopathy is the most common cause of blindness in individuals with diabetes due to the damage it causes to the retinal blood vessels. This damage leads to vision loss and can result in blindness if not treated promptly.

Why the Other Options Are Incorrect:

1. Corneal Opacity: Not common in diabetes and does not typically lead to permanent blindness.
2. Conjunctivitis: It is a temporary condition and does not cause blindness.
3. Lens Dislocation: Rare in diabetes and doesn’t cause blindness like diabetic retinopathy.
4. Glaucoma: Though diabetes can increase the risk of glaucoma, it is less common than diabetic retinopathy as a cause of blindness.

The patient described here has HIV and presents with dysphagia (difficulty swallowing) and a whitish pseudomembranous lesion on the oropharynx and tongue. The important feature in this case is that the pseudomembrane can be scraped off. Let’s examine the options in relation to the description:

Oral Candidiasis (Most Likely Diagnosis)

• Cause: Oral candidiasis is caused by the overgrowth of the yeast Candida albicans in the mouth, especially in immunocompromised individuals such as those with HIV.
• Presentation: It commonly presents as white, curd-like lesions on the tongue, the roof of the mouth, or the oropharynx. These lesions are pseudomembranous and can be scraped off, revealing an erythematous (red) base beneath.
• Relevance to HIV: HIV patients are more prone to oral candidiasis due to their compromised immune systems. This is a very common opportunistic infection seen in HIV-positive individuals.
• Conclusion: Given the white pseudomembranous lesions that can be scraped off, along with the patient’s immunocompromised status due to HIV, oral candidiasis is the most likely diagnosis.

Erythroplakia

• Cause: Erythroplakia is a red, velvety lesion in the mouth or oropharynx that is considered precancerous. It is often linked to tobacco use or other irritants.
• Presentation: Erythroplakia is not white and does not form a pseudomembrane that can be scraped off. It tends to be flat or slightly raised, and is associated with an increased risk of squamous cell carcinoma.
• Conclusion: This does not match the patient’s presentation of white pseudomembranous lesions, and thus is not likely.

Herpes Labialis

• Cause: Herpes labialis is caused by the Herpes Simplex Virus (HSV), typically affecting the lips and sometimes the oropharynx.
• Presentation: HSV presents as painful, fluid-filled vesicles that may later ulcerate, often around the lips or genital region, rather than a white pseudomembrane in the oropharynx.
• Conclusion: This patient’s presentation of white pseudomembranous lesions that can be scraped off does not fit with the typical presentation of herpes labialis, so this diagnosis is unlikely.

 None of Them

• This option suggests that none of the listed conditions apply to the patient’s presentation. However, the patient’s symptoms and physical findings are consistent with oral candidiasis, so this option is incorrect.

 Leukoplakia

• Cause: Leukoplakia is a white patch that forms on the mucous membranes of the mouth, usually due to chronic irritation (e.g., smoking, alcohol use).
• Presentation: The lesions are white and cannot be scraped off. Unlike oral candidiasis, leukoplakia is not a pseudomembrane and is generally not associated with a superficial layer that can be removed easily.
• Conclusion: Leukoplakia does not match the description of scrapable white lesions, so it is unlikely in this case.

Final Answer: Oral Candidiasis

Given the HIV status, whitish pseudomembranous lesions in the oropharynx and tongue, and the fact that these lesions can be scraped off, oral candidiasis caused by Candida albicans is the most likely diagnosis.

This patient presents with a slow-growing, painless, mobile mass located in the parotid region, which is highly suggestive of a benign salivary gland tumor. The biopsy findings further confirm the diagnosis:

• Ductal epithelial cells
• Myoepithelial cells
• Cartilage in a myxoid stroma

These histological features are hallmarks of pleomorphic adenoma, the most common benign tumor of the salivary glands, especially the parotid gland.

Since pleomorphic adenoma presents as a painless, slow-growing mass with mixed histological features, the correct answer is:
✅ “Pleomorphic adenoma”

Why the Other Options Are Incorrect:

1. Acinic cell tumor – ❌ Incorrect

   • This is a rare malignant salivary gland tumor that usually involves the parotid gland but does not show a myxoid or cartilaginous stroma.

2. Burkitt lymphoma – ❌ Incorrect

   • Burkitt lymphoma presents as a rapidly growing mass, often associated with Epstein-Barr virus (EBV) and found in the jaw or abdomen, not in the parotid gland.

3. Mucoepidermoid carcinoma – ❌ Incorrect

   • The most common malignant salivary gland tumor.
   • It contains mucinous and epidermoid (squamous) cells but lacks the cartilage and myxoid stroma seen in pleomorphic adenoma.

4. Squamous cell carcinoma – ❌ Incorrect

   • This presents as a firm, irregular, often ulcerated mass, commonly associated with smoking, sun exposure, or HPV, and does not have the mixed histological features seen in pleomorphic adenoma.

Distichiasis is a condition where an extra row of eyelashes (accessory eyelashes) grows from the meibomian gland openings along the eyelid margin. These abnormal eyelashes may irritate the cornea and conjunctiva, leading to discomfort, tearing, redness, and corneal damage.

It can be:

• Congenital – Due to a genetic mutation (e.g., FOXC2 gene in lymphedema-distichiasis syndrome).
• Acquired – Due to chronic inflammation, trauma, or eyelid diseases.

Since distichiasis means an accessory row of eyelashes, the correct answer is:
✅ Accessory row of eyelashes

Why the Other Options Are Incorrect:

1. “Misdirected eyelashes” – ❌ Incorrect

   • This describes trichiasis, where normal eyelashes grow in the wrong direction, rubbing against the eye.

2. “Outward protrusion of eyelid” – ❌ Incorrect

   • This describes ectropion, a condition where the eyelid turns outward.

3. “Excessive sweating” – ❌ Incorrect

   • This describes hyperhidrosis, which is unrelated to eyelashes.

4. “Downward drooping of upper eyelid” – ❌ Incorrect

   • This describes ptosis, which is caused by levator palpebrae superioris dysfunction.

Cephalohematoma is a subperiosteal hemorrhage that occurs between the skull bone and the periosteum. It is caused by trauma during birth, often due to pressure on the infant’s head during delivery (e.g., forceps or vacuum-assisted delivery).

Key Features of Cephalohematoma:

•Location: Blood collects between the skull and periosteum, meaning it is confined to a single bone (usually the parietal bone).

•Does NOT cross suture lines, as the periosteum is tightly attached at the sutures.

•Resolves over weeks to months as the blood is gradually reabsorbed.

•No discoloration of skin (unlike caput succedaneum, which is more superficial).

Since the fluid (blood) is present between the skull and periosteum, option 4 is the correct answer.

Why the Other Options Are Incorrect:

1.“Dura and arachnoid”  ❌ Incorrect

•Bleeding between the dura and arachnoid results in a subdural hematoma, which is a different condition (often due to tearing of bridging veins).

2.“None of these” ❌ Incorrect

•Cephalohematoma does exist, and option 4 correctly describes it.

3.“Dural folds” ❌ Incorrect

•The dural folds (e.g., falx cerebri, tentorium cerebelli) are intracranial structures, unrelated to cephalohematoma.

4.“Arachnoid and pia” ❌ Incorrect

•Bleeding between the arachnoid and pia leads to a subarachnoid hemorrhage, typically due to ruptured aneurysms or trauma, NOT birth injury.

 Pleomorphic adenoma is the most common benign tumor of the salivary glands. It accounts for about 60-70% of all benign salivary gland tumors. It typically affects the parotid gland, but can also occur in the submandibular and minor salivary glands. Pleomorphic adenomas are characterized by a mix of epithelial and mesenchymal-like tissue, and they often present as slow-growing, painless masses.

Why the other options are incorrect:

• Warthin tumor: Although Warthin tumor (also known as papillary cystadenoma lymphomatosum) is a common benign tumor of the parotid gland, it is not as common as pleomorphic adenoma. Warthin tumors typically occur in older adults and are associated with smoking.

• Adenoid cystic carcinoma: This is a malignant tumor, not benign. It is an uncommon type of cancer that primarily affects the minor salivary glands but can also involve larger glands like the parotid.

• Sialadenitis: Sialadenitis refers to inflammation of the salivary glands, usually due to infection, and is not a tumor. It can cause swelling and pain but is not a neoplasm.

• Parotid gland oncocytoma: Oncocytomas are rare benign tumors of the parotid gland. While they can occur, they are much less common than pleomorphic adenomas.

 Loss of heterozygosity (LOH) at 17p is a genetic alteration commonly associated with the deletion or inactivation of the p53 gene. This mutation causes the dysplastic transformation of cells and is linked to various cancers. The p53 gene plays a key role in regulating the cell cycle, apoptosis, and DNA repair. When it is inactivated or lost, cells may proliferate uncontrollably, leading to the development of tumors.

Why the other options are wrong:

• Rb (Retinoblastoma protein): The Rb gene is located on chromosome 13, not 17. It is also involved in the regulation of the cell cycle, but its loss typically results in the development of retinoblastoma and other cancers, not dysplastic transformations triggered by LOH at 17p.

• pTEN: The pTEN gene is located on chromosome 10 and is involved in regulating cell growth by acting as a tumor suppressor. While mutations in pTEN can contribute to cancer, they are not directly linked to LOH at 17p.

• p16 (INK4a): The p16 gene is located on chromosome 9 and is involved in cell cycle regulation. While it is a tumor suppressor, its loss typically leads to the development of various cancers, but it is not associated with LOH at 17p.

• None of them: This is incorrect because LOH at 17p is strongly linked to the p53 gene, as explained above.

Pleomorphic adenoma is the most common benign tumor of the parotid gland, accounting for about 60–70% of all parotid tumors.

•It arises from both epithelial and myoepithelial cells, giving it a mixed histological appearance (hence the name “pleomorphic”).

•It is slow-growing, painless, and typically presents as a firm, mobile mass in the preauricular region.

•While benign, long-standing pleomorphic adenomas can undergo malignant transformation into carcinoma ex pleomorphic adenoma.

Why the Other Options Are Wrong:

1.Acinic cell carcinoma:

•This is a malignant tumor, not benign.

•It arises from serous acinar cells and is relatively rare compared to pleomorphic adenoma.

2.Myoepithelioma:

•A rare benign tumor arising from myoepithelial cells.

•It is much less common than pleomorphic adenoma.

3.Canalicular adenoma:

•A benign tumor, but it occurs more commonly in the minor salivary glands (especially upper lip) rather than the parotid gland.

4.Basal cell adenoma:

•Another benign tumor, but it is less common than pleomorphic adenoma.

•It originates from basal cells of the salivary gland ducts and is usually found in older adults.